Important Questions In a Telecommunication Entry Level Job Interview

Network Plan and Optimization Test Paper

I.             Fill in the blanks :

1.     In radio signal propagation, there are two kinds of signal fading. The fading caused by buildings shadow is called                        .The fading caused by multi-path is called                            

2.     In GSM mobile communication system, there are mainly four kinds of diversity technology: space diversity,          ,      ,        diversity.

3.                 Mainly refers to the problem of co-frequency interference arising from the time difference between master signals arriving at the receiver and other multi-path signals in terms of time for transmission in space (transmission distance).

4.     In a GSM 900 cellular BTS, its Tx band is    MHZ, and its Rx band is    MHZ; its duplex interval is    MHZ, and its Carrier Frequency interval is     KHZ , each Carrier Frequency containing       full-rate physical channels.

5.     Demodulation is actually a process to reflect the change to the transferred information about such Carrier Frequency parameters as    .

6.     Electronic map mainly includes such three subdirectories as   、   、, which keep the information ASSET can use.

7.     In GSM specification, despite what frequency reuse pattern is applied, Carrier/Interference must satisfy following request. Co-frequency C/I ≧     dB. Adjacent frequency C/I ≧     dB. 400KHZ deviation C/I ≧    dB. In engineering design,       dB more should be considered.

8.     The multiple access modes now adopted in wireless communications include     ,   , and    

II. Signal Choices

1.        The Common Propagation Models applied to 1800 MHz macro cellular predication is (      )

A. Okumura-Hata                                         B. Cost231-Hata

C. Cost231 Walfish-Ikegami                 D. Keenan-Motley

2.        Attenuation of 7/8 inch feeder is about ______ dB/100m at the frequency 890MHz . (     )

A. 4.03                 B. 2.98             C. 11.2                D. 6.87

3.        Supposing there is 10M frequency band, and 4*3 is used, what is the site configuration supported at most?  (   )

A. S3/3/3         B.S4/4/4                 C. S4/4/3        D. S3/3/4

4.        Which method of LAC definition is incorrect? (   )

A. One BSC with one LAC;                                

B. One BSC with two LAC;

C. Two BSC belong to different MSC, with the same LAC; D. Two BSC under the same MSC, with the same LAC.

5.        In the GSM system, the interface between the BSC and MSC is ( )

    A. A interface B. Abis interface     C. Um (radio) interface            D. E interface

III. Multiple Choice

1.     Which descriptions in the follow are correct : (    )

A. Loss in the area with window zone is generally more than that without window zone.

B. The average penetration loss in urban buildings is less than those in suburb areas and remote areas.

C. Loss in the open area within buildings is more than that in the wall area with corridors.

D. Generally speaking, 1800MHz level difference between indoors and outdoors is larger than 900MHz.

2.     ASSET network planning tool can provide (    )functions

     A. Coverage prediction                        B. MRP Frequency planning

C. Model adjustment            D. Statistics Analysis

3.     The digital map used for mobile communication includes the following :  

 ( ).<0}

A. Digital topography model (UTM)     

B. Ground coverage model (DOM data)

C. Building space distribution model (BDM model)

D. Digital elevation model (DEM data)

4.     Which of the following interfaces are standard? (  )                                                     

A. Um                      B. Abis   C. A                   D. Pb

IV. True or False

1.      Diversity technique can provide 10~15 Db diversity gain.  ( )

2.      In general, the base station antenna in populous urban areas should be as high as 40～50 meters but it is 25～30 meters in the suburbs. ( )

3.      Plains & rural areas, for Directional station, Generally, select an antenna of 90 degrees or of 120 degrees. It is perferred to use vertical single  polarization antenna. ( )

4.      Suburb area, for Directional station, Normally, select antennas with high gains, permitting of electrically adjustable azimuth or mechanical downtilt angle.In addition, if some areas are not well covered in some directions, antennas with its horizonal half power beam width of 90 degrees may be selected. ( )

5.      The designed station address should be kept far away from the forest so as to avoid the fading of receiving signals. ()

6.      When the frequency hopping is not used, it is better make the frequency interval between TCH in the same cell higher than 400K. ( )

7.      In 1*3 multiplexing mode, the direct adjacent base station can not have the same frequency. ( )

8.      Usually, the propagation loss of GSM1800 is higher than that of GSM 900 by 6~10 dB. ( )

9.      The capacity of a cellular system is limited by the interference from frequency multiplexing. ( )

10.    The maximum data transfer rate of GPRS is 160K, and that of 3G is: 384K when moving at a high speed, and 2M. When static ( )

V.  Please answer questions briefly

1.  Describe According to the labels of location updating in the network, there are three types of location updating, please list them and describe the main characteristic.( 3 Scores)

2.  There is a  S1/1/1 site with 6 TCH channels in each cell, supposing the block rate is 0.03%,and Average busy hour traffic per user is 0.025Erl.(5 Scores)

Please calculate:

(1). the total traffic of the site.

(2). the total number of subscribers the site can support.

3.  Please list the possible reasons to make cell’s TCH congestion rate high. (3 scores)

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